In process automation technology, field devices are often applied, which serve for registering and/or influencing process variables. Examples for such field devices include fill level measuring devices, mass flow measuring devices, pressure- and temperature measuring devices, etc., which, as sensors, register the corresponding process variables, fill level, flow, pressure, or temperature.
Serving for influencing process variables are actuators, e.g. valves or pumps, via which the flow of a liquid in a pipeline section, or the fill level in a container, can be changed.
Referred to as field devices are, in principle, all devices, which are applied near to the process and which deliver, or process, process relevant information.
A large number of such field devices are produced and sold by the firm, Endress+Hauser.